The field of the present disclosure relates generally to a stack design for batteries and a method of assembling a battery stack. More particularly, the present disclosure relates to a molten salt based battery stack design and method of assembly.
Ordinary stack designs include a plurality of a repeating unit of a bipolar plate, an anode, a base and a cathode. Ordinary stack designs typically are either a tubular type stack design or a planar type stack design. Multiple arrangements of the repeating unit form a stack having a designed voltage and current.
Tubular type stack designs comprise a series of concentric cylinders. The tubular type stack design typically includes concentrically arranged cylinders of a bipolar plate, anode, base and cathode. Tubular type stack designs thus resemble a cylindrical tube shape. Due to the shape of the tubular type stack design, the tubular type stack design has a high resistance (i.e., lower efficiency) compared to a planar type stack design, for example due to an increased travel distance of electrons.
Planar type stack designs comprise a series of parallel flat (i.e., planar) layers. The planar type stack design typically includes a repeating parallel layering of a bipolar plate, anode, base and cathode. Planar type stack designs may have a higher efficiency than tubular style stack designs due to a shorter electron travel distance. However, planar type stack designs require that seals be placed between each of the layers of the stack. In a planar type stack design, the seals contact the corrosive materials of the stack, such as a molten salt. Due to the seals contacting the molten salt, the seals may fail. In addition, planar type stack designs may include a base formed of a brittle material. Thus, planar type designs may include a base having an increased thickness in order to avoid undesirable cracking or breaking caused by pressure induced deformation. However, increasing the thickness of the base results in reduced efficiency, for example due to an increased travel distance of electrons.